This invention relates to methods of preservation of biological material for extended periods. Additionally, the invention relates to methods of determining the optimum temperature at which to store biological materials for extended periods.
It is known in the art that biological material can be stored at reduced temperatures to decrease the rate of deterioration of the biological material. The low temperature inhibits the activity of degradation enzymes in the biological material as well as inhibiting the growth of microorganisms which degrade the material. Currently available technologies can be divided into two categories. The first category includes storage of the material in an unfrozen state. Customarily, the biological material is stored at temperatures between 0xc2x0 C. and 10xc2x0 C. The second category of storage includes storage of the biological material in a frozen state. Customarily, the material is stored at a temperature of xe2x88x9215xc2x0 C. or less.
The existing technologies suffer from serious defects. Storage of biological material at temperatures between 0xc2x0 C. and 10xc2x0 C. extends the usable lifetime of the material. However, the extension is of a limited duration. Generally, biological material begins to undergo a noticeable amount of deterioration in one or two days and becomes completely unusable after two or more days. This places major constraints on the availability of fresh materials such as foodstuffs and other biological materials. The materials must be produced close enough to the location at which they will be sold so that an adequate usable life time remains after shipping.
Freezing of material overcomes some of the difficulties inherent in shipping fresh materials. Once frozen, the material may be stored for protracted periods and shipped over long distances. In the process of freezing, the formation of ice crystals within the material results in damage to the material, which reduces the quality of the material. The reduction in the quality of material stored in the frozen state results in a reduction in the value of the material relative to the fresh, unfrozen state.
Thus, there is a need in the art to provide a method for the extended storage of biological material with no loss of the usability or quality of the material. Such a method would find broad applicability, for example, in the handling of foodstuffs, cut flowers, cells, tissues, gametes, organs, and whole organisms. The present invention will be useful in the handling of all types of foodstuffs. The present invention is particularly useful for the storage of fresh produce, such as carrots, mushrooms, apples, onions, kiwis, citrus fruits, broccoli, tomatoes, and garlic. The present invention is equally useful for the storage of fresh caught seafood, such as shrimp, scallops, tuna, salmon, lobster, crab, oysters, and other fresh caught fish. The present invention is also useful for the storage of meat, such as chicken, beef, pork, lamb, and other types of meat. The invention is particularly suited for prepared cuts of meat, such as steaks, chicken breasts, hamburger, and fish fillets. The invention may also be used to store whole carcasses for shipping.
One object of the invention is to provide a methodology for determining the optimum bio-storage temperature of biological materials. This method includes the step of determining the melting point depression of the material to be stored.
An object of the invention is to provide a method of storage of biological materials comprising the steps of determining the melting point depression of the biological material and storing the biological material at a temperature greater than the melting point depression and less than 0xc2x0 C.